Draft equalizer for gas burners



Juiy 27' J. w. MARTIN DRAFT EQUALIZER FOR GAS BURNERS Filed April 50,1955 Patented July 'UNITEDSTATES DRAFT EQUALIZER Foa GAS BURNERS JamesWoodward Martin, Dallas, Tex; assignor to Lone Star Gas Company, Dallas,Tex., a

corporation of Texas Application April 30, 1935, Serial No. 19,115

5 claims; (01. 110-147) My invention relates to new and usefulimprovements in a draft equalizer for gas burners and the presentapplication is a continuation in part of my co-pending applicationSerial No. 731,231, filed June 19, 1934.

The object of this invention is to provide a gas burner adapted forvarious uses and equipped with means for preventing sudden changes inatmospheric conditions from extinguishing the pilot or creating a backdraft on the flue through which the products of combustion aredischarged.

' A further object of the invention is to provide means for equalizingthe pressure in the exhaust and intake conduits, thus preventing theblowing out or sucking out of the flame.

With the above and other objects in view which will appearas thedescription proceeds, my

invention resides in the novel features hereinset forth, illustrated inthe accompanying drawing and more particularly pointed out in theappended claims.

Referring to the drawing in which numerals of like character designatesimilar parts throughout the several views,

Fig. 1 is a view in side elevation, partly broken away showing one formof my invention in stalled in connectionwith, a liquefied petroleum gasvaporizing apparatus of the type shown and described in my co-pendingapplication filed of even date herewith, Serial No. 19,114.

Fig. 2 is an enlarged connecting end view of the draft equalizer shownin Fig. 1.

Fig. 3 is a view in side elevation of the same.

Fig. 4 is a sectional view taken on line 4-4 of Fig. 3, and,

Fig. 5 is an enlarged sectional view of a modification constituting thepreferred form of draft equalizer.

In the drawing, referring toFig. '1, numeral l represents a gas burnerof any suitable type having a conventional pilot 2, said burner andpilot being fed from any suitable source and housed in a box or casing3, the latter having a door I which is adapted to be firmly securedinplace by a nut and bolt arrangement 5 of any convenient type. Theburner box 3 in the adaptation shown in the drawing, islocatedlimmediatelybeneath the bottom wall of a receptacle 6 containingthe fluid to be heated, a flue 'I extending upwardly through the bottomwall of said receptacle for a predetermined distance and then beinginclined downwardly with its inclined end projecting outwardly from saidreceptacle and terminating in communication with a draft equalizer 8hereinafter referred to more in detail.

.The rear wall of the burner box 3 is provided with a suitable openingfor receiving the end of an air intake conduit 9, the other end of whichterminates in communication with said draft equalizer 8. v

Referring to Figs. 2 to 4, inclusive, the form of draft equalizer hereshown consists of a housing having upper side walls Ill and II, lowerside walls I2 and I3, and end walls I4 and i5.

, The connecting end wall i4 is provided with two openings l6 and I!into which the ends of the air intake conduit 9 and the exhaust conduitor flue I are respectively connected, a transverse vertical partitionYl8 being arranged substantially centrally of the housing between saidopenings to form intake and exhaust chambers lie and Ha, respectively.

The upper end of the housing is provided with an exhaust opening l9between adjacent ends of theside walls In and II, and the lower end ofsaid housing is provided with an intake opening 20 between adjacent endsof the side walls I! and I3. Just inside the mouth of each of theseopenings and extending entirely across the housing, I provide an angularbaffle l9a and 20a, respectively, to interrupt any sudden influx of airthrough said openings.

The four side walls of the housing are provided with openings Ilia, Ila,Ma and Ba, respectively, and adjacent each of these openings I providebaffle plates 2| which lie within the respective chambers and extendtransversely across the housing with their adjacent ends in spacedrelation, as clearly shown in Figs. 2 and The flue I is preferablyprovided with a drain outlet 22 (Fig. 1) adjacent the point where itemerges from the receptacle 6, a dam or obstruction 23 extending acrossthe lower portion of the flue immediately posterior to the drainopening, whereby any condensation in the flue is drained out before itreaches the draft equalizer 8. This apparatus is usually. located out ofdoors, and in extreme weather any moisture entering the draft equalizerwould freeze and eventually obstruct one or more of the openingstherein.

, In the operation of this form of draft equalizer, the products ofcombustion from the flue 'l are discharged into chamber lla throughopening l1, thence through the spaces between the baflies II andpartition l8, exhausting to atmosphere through openings l9, Ila and Ba.Fresh air is drawn intochamber lGa by the draft created by and Ila andprevents any appreciable mixtureof the products of combustion with thefresh air taken into the burner. The baflles l9a, 20a and 2| prevent anyoutside atmospheric disturbances from passingunobstructed through thevarious openings into the chambers Mia and I la.

With these bailies and openings arranged in staggered relation, nooutside atmospheric dis- \turbances are transmitted directly into thechambers. For example, in the case of changing wind velocity which isordinarily the most serious of these atmospheric disturbances, the windsare caused to disperse and distribute themselves throughout the outerspace between the bailies 2| and the walls of the housing, so that theeffect of such disturbances is distributed simultaneously and with thesame intensity to both chambers I61: and Na, thus affecting an equal andbalanced pressure throughout the combustion system including the draftequalizer and the burner box. Obviously, under these conditions i theflame is allowed to create its own positive draft regardless of outsideatmospheric disturbances.

In Fig. 5 I have shown a device which operates upon the same principleas that just described but due to its simplicity, this modification isthe form which I prefer to use in most instances.

This device consists of a cylindrical housing 24 which is verticallydisposed in place of the draft equalizer 8 just described, with the flue1 connected into an L 25 which projects through the wall of the housing24 with its open end directed upwardly, and the air intake conduit 9connected into a similar L 26 extending through the wall of the housingwith its open end directed downwardly. It will be noted that in thisform of my invention the flue and air intake conduits are verticallyspaced instead of being located side by side as in Fig. 1. However, theimportant feature is to arrange the open ends of the Ls 25 and 26 invertical alignment substantially in the central portion of thecylindrical housing 2.

The ends of the housing 24 are open as at 21 and 28-and provided withdeflectors or bailles 21a and 28a, respectively, which may be secured tothe walls of the housing by any suitable means such as brackets 29, saidbailles extending across the open ends of the housing and spacedtherefrom a predetermined distance to provide for suflicient intake andexhaust.

This form of my invention provides an effec- 'tive means of equalizingatmospheric disturbances, and as in the structure just described,permits the burner to create its own positive draft. The hot products ofcombustion leaving the burner box 3 through flue I are conductedupwardly through the L 25 into the upper portion of the housing 24,being discharged through the space between the baille 21a and the upperend 21 of-the housing. Fresh air is drawn in through the open lower end28 of the housing, past the baiiie 2811 into the down-turned end of theL 26 and from thence ,through conduit 9 into the burner box.

Obviously, any wind disturbances are interrupted by the baflles 21a and28a, and due to the aosmas arrangement of the L's, their effect isequall distributed in the housing 24 so as to permit tlu uninterruptedoperation of the burner.

While I have shown and described my preseni invention as particularlyadapted. for use in connection with liquefied petroleum gas vaporizer:of the type shown and described in my copending applications, it is tobe understood that I do not intend to limit-myself in any way to thisparticular use. Obviously, this invention may be used with equal eflectin connection with any type of gas burner which is subjected to changingatmospheric conditions, such for example as orchard heaters and otherburner equipment which is located out of doors and exposed to theelements.

From the foregoing it is believed that the construction and operation ofmy invention may be readily understood by those skilled in the artwithout further description, it being borne in mind that numerouschanges may be made in the details disclosed without departing from thespirit of my invention as set out in the following claims.

What I claim and desire to secure by Letters Patent is:-

1. The combination with a fuel burner having an air inlet conduit and aflue, of a draft equalizer comprising a housing, exhaust openings andintake openings in said housing, baflie means adjacent saidopenings, theouter ends of said air conduit and flue projecting through the wall ofsaid housing and terminating within the latter, and separate means forpreventing the admixture of flue gases with the fresh air drawn intosaid conduit.

2. In combination with a fuel burner, a closed burner box, an air inletconduit leading into said box, a flue leading from said box, a draftequalizer, including a housing, intake and exhaust openings in saidhousing, baifles adjacent said openings, said conduit and flue leadinginto said equalizer, and means within said equalizer for preventing theadmixture of flue gases with the fresh air drawn into said conduit.

3. The combination as claimed in claim 2 wherein said housing comprisesa vertically disposed body portion open at its upper and lowerextremities, said flue terminating in an upturned end and said air inletconduit terminating adjacent said flue in a down-turned end.

I 4. The combination 'as claimed in claim 2 wherein said housingcomprises a vertically disposed body portion open at .its upper andlower extremities, said flue terminating in an upturned end and said airinlet conduit terminating below said flue and in vertical alignmenttherewith, in a down-turned end.

5. The combination with a fuel burner having an air inlet conduit and aflue, of a draft equalizer comprising a housing, a vertical partitiondividing said housing into an inlet chamber and an exhaust chamber, saidair inlet conduit being in communication with said air inlet chamber,said flue being in communication with said exhaust chamber, inlet andexhaust openings for said chambers, and baflie means adjacent saidopenings, said chambers being arranged in indirect communication withone another whereby atmospheric disturbances are equally distributedthroughout said housing but the admixture oi flue gases with the freshair is prevented.

JAMES WOODWARD MARTIN.

